S.D. Codified Laws § 46-5-6
In the issuance of permits to appropriate water for irrigation or in the adjudication of rights to the use of water for such purpose, the amount allowed may not be in excess of the rate of one cubic foot of water per second for each seventy acres, or the equivalent thereof, and the volume of water diverted for use may not exceed two acre-feet per acre, delivered on the land for a specified time each year. The Water Management Board may allow a greater diversion, in volume or rate or both, if the method of irrigation, any time constraints on diversion of water, or the type of soil so requires. However, no annual volume may be greater than three acre-feet per acre delivered to the land. The above rate of one cubic foot per second for each seventy acres does not apply in cases of flood water at such times when the flow of the stream is much in excess of the total recorded and approved rights on the stream.
SDCL 46-5-6